Humans are mammals. I do not think OP implied those emotions are unique to humans, rather the opposite is true. All species of (vertebrate) social animals evolved a similar set of emotions, in part due to shared ancestry but in part on the basis of being subject to the same environmental pressures.

nice point! mammal territorial anger is cooperative - go away or else. it can avoid an expensive fight. fear is backing down - i'll go. this communication is a kind of cooperation.

this explains the exhibition of some emotion, and argues that that's all it is. though, there are non-social emotions that are useful, eg hunger, fear of high places, enjoyment of warmth in cold weather.